Contrast-to-noise ratio (CNR)

Definition: The contrast-to-noise ratio (CNR) is the detection sensitivity per sampling unit. In the context of fNIRS, this can refer to the ratio of the amplitude variation I of a hemodynamic response to the level of noise in the data, i.e. CNR=I/ or in the context of general image data analysis, it can refer to the average signal/intensity recovered in a selected region-of-interest (ROI) subtracting that of the background region, and divided by the spatial variations of the recovered image data in either the background or ROI.

Alternative definition:



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Related terms: signal-to-noise ratio, noise  

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